A receptor binding assay directed separation has led to the identification of a minor alkaloid 6-methoxy- N-methyl-1,2, 3,4-tetrahydro-beta-carboline (1) from the Chinese herbal drug Evodiae Fructus [EF, the dried, unripe fruit of Evodia rutaecarpa Look. f. et Thomas (Rutaceae)]. The structure of compound 1 was elucidated by means of spectroscopic methods and a comparison with synthetic materials. Compound 1 interacted with 5-HT (1A) and 5-HT (2) receptors with a moderate K (i) value of 78 and 1.2 microM, respectively. Compound 1 is found in EF and the genus Evodiae for the first time.